Effects And Mechanisms Of Tea Polyphenols And Lactobacillus Brevis M8 On Growth Performance Of Yellow Feather Broiler

In order to improve the survival rate of broilers and reduce the happening of the disease,antibiotics have been widely used.Antibiotics residue in meat and meat products become important food safety hidden trouble.In order to reduce the use of antibiotics during chicken breed tache,and improve the quality and processing characteristics of chicken,looking for effective feeding probiotics and plant natural products to improve the growth performance and meat quality of broilers become the hot spot in the industry.On the basis of tea polyphenols?Tea Polyphenols,TP?affecting the composition of gut microbes on model rats and the effect of TLRs,Lactobacillus brevis M8 strains isolated from fresh milk with the compatibility filling TP for feeding chicken.The growth performance,meat quality,cytokines and the influence of calcium protease is express etc of Yellow feather chicken were studied and the main research results as follows:1.TP modulatory effect on rat faecal microbiota and TLRs expression in colonAfter 6 weeks lavage,the Lactobacillus quantity had a tendency to be reduced with feeding time.when samples from both groups were considered together.There was a significant differences in microbiota composition.The TP-fed animals had a significant decrease in the proportion of Bacteroides,Staphylococcus and Clostridium genera compared to the control group at the end of the study and with respect to their initial values?p<0.05?.It was revealed that TP can regulate the composition of intestinal microflora.Compared with control group,TLR4 gene expression in colon was not modified by TP-fed rats whereas TLR2 and TLR7 gene expression had a trendence to be reduced?p<0.01?.TP-fed animals showed four fold downregulation in the TLR9 expression in comparison to the referance group?p<0.05?.The decrease of TLR2 and TLR7 in TP group may be related to the decrease of Lactobacillus,Bacteroides and Bifidobacterium.After 6 weeks of the TP lavaging,the IgA concentration in the small intestine washes from the TP animals was significantly reduced when compared to that of the CK group?p<0.05?.The former one was correlated with a decrease in the number of cells of in the genus Clostridium and Streptococcus groups?p<0.05?.The colon IgA gene expression in those animals receiving TP for 6 weeks followed the same down-modulatory pattern?p<0.05?.This decrease also had significant correlations with the content of Bacteroides,Bifidobacterium,Streptococcus and Clostridium in the TP group?p<0.01?.Faecal samples collected before the start of the diet and at the end of the study were used to determine IgA-and IgM-coating bacteria.Although IgM-coating bacteria were not detected in intestinal samples,both groups showed a similar IgA-coating bacteria pattern at baseline.It can be inferred that TP could regulate the body's immune response by adjusting the composition of the intestinal microbial flora presumably.2.Characteristics of L.brevis M8 as probioticsThe vitro test results showed that M8 strains had a good inhibitory effect on E.coli O157:H7 and s.typhimurium CICC 21482 with the inhibitory rate of 99.73%and 99.54%,respectively.The results speculated that the M8 strain have the ability to reduce the usage of antibiotics indirectly,and improve the safety of the broiler.The M8 suspension-fed broilers had significantly higher protease activities?p<0.01?,muscular stomach,and the amylase and lipase activity of the small intestine?p<0.01?,pancreas?p<0.05?,were significantly improved.M8 strains could promote the digestion ability of broilers.Compared with the control group,the lysozyme activity of broilers inoculated with M8 bacterial suspension increased by 9.28%?p<0.05?,the total protein content increased by 11.43%?p<0.05?,albumin Content increased by 14.69%?p<0.05?,respectively.Those results prompted that the M8 strains could improve the nonspecific immune function of broiler.3.TP and M8 strains compatibility effect growth performance of broilerCompared with the control group,TP and M8 compatibility or respectively fed for28⁵6 days,the indicators of body weight and gain weight of broilers had slow down.The results of feed to weight of broiler were shown that Feed conversion would reduced after lavaging 10⁸ CFU kg^-1?BW M8 With the combination of 0.06 g kg^-1?BW TP for feeding42-49 days,which might have the effect of reducing weight directly and abdominal fat rate indirectly,therefore,the contradiction between the poultry production and quality would be solved though this way.4.TP and M8 strains compatibility effect meat quality of Yellow feather broilerThe chicken breast muscle sample was collected to test the meat quality indexes at the age of 56.The results showed that:1)0.03,0.06 g kg^-1?BW TP and 10^8 CFU kg^-1?BW M8compability could significantly improve meat color?p<0.05?.Cooling within 24 hours,pH values of all of experiment groups were maintained among 6.31⁶.74?p>0.05?,which could effectively avoid the formation of PSE meat.In addition,M8 and TP compatibility or respectively could markedly slowed drip loss,and the CAPNs expression were significantly increased after lavaging M8 or/and TP?p<0.05?,and the dose of TP suspension was positively correlated to CAPNs expression.2)EAA content of broiler meat among40%⁴1%after M8 or TP lavaging.The retio of EEAA to NEAA between 0.70⁰.71,which completely accords with the recommended standards of the FAO/WHO were 40%and 0.6.TP combined with M8 lavaging better than M8 separately lavaging for significantly increased TAA or EAA content compared with control group.On the whole,M8 strains and TP compatibility had positive effect to improve poultry processing properties and nutrition in those experimental conditions.5.TP and M8 strains compatibility effect immune performance and serum biochemistry indexes of Yellow Feather broilerThe blood,immune organs and other samples were collected during the 56 days of chicken to test the biochemical or immune indexes,and the results were shown:1)TP or/and M8 lavaging could significantly increased immune organ index of poultry?p<0.05?,The spleen and bursa of fabricius indexes of broiler were increased hightest by lavaging 10⁸ CFU kg^-1?BW M8 combined with 0.06 g kg^-1?BW TP,of which the content were 23.24%,19.59%respectively.The thymus index was increased most by lavaging 10⁸,10¹⁰CFUkg^-1?BW M8 combined with 0.06 g kg^-1?BW TP,and 10⁸ CFU kg^-1?BW M8 combined with 0.09 g kg^-1?BW TP respectively.This might be associated with M8 and TP interactions.2)The cytokine levels of broilers were significant differences after lavaging TP or/and M8?p<0.05?.The content of IL-1,IL-4,TNF-?,IFN-?were significantly rised?p<0.05?,On the contrary,the content of IL1-?was lower significantly?p<0.05?.The effect of the composite lavaging were better than the single lavaging,of which,10⁸CFU kg^-1?BW M8 combined with 0.06g kg^-1?BW alvaging broiler for 6 weeks had best effect.This may be related to adjustment of intestinal microbial flora in poultry of by M8 strains.As well as the secretion of Slps from M8 strains as antigen on intestinal epithelial cell recognition.To sum up,the immune organ index and the level of cytokines of broiler after lavaging for 6 weeks were improved better than for 8 weeks,which provided a certain reference for choosing poultry market time.3)M8 or/and TP lavaging could significantly reduce the content of LDL,TG and CHO in serum?p<0.05?,among them,the 10⁸ CFUkg^-1?BW M8 combine with 0.06g 10⁸ CFU kg^-1?BW TP lavaging could low the content of LDL best,and 10⁶ or 10⁸ CFU kg^-1?BW M8combined with 0.06g kg^-1?BW TP and 10⁸ CFU kg^-1?BW M8 combined with 0.03g kg^-1?BW could low the content of CHO best?p<0.05?,and kg^-1?BW M8 combined with 0.06 g kg^-1?BW TP low TG best?p<0.05?.Therefore,0.06 g kg^-1?BW TP combined with 10⁸ CFU kg^-1?BW M8 lavaging could significantly reduce serum cholesterol.The effect of hypolipidemic of TP and M8 was confirmed,which was beneficial to their antioxidant properties.